HMS Challenger (K07): A Cold War Nuclear Recovery Ship That Ended Up Mining Diamonds

Built to Replace an Ageing Predecessor

HMS Challenger was built by Scotts Shipbuilding and Engineering at Greenock, launched on 19 May 1981 and commissioned in 1984, a purpose-built diving support vessel intended to replace the ageing HMS Reclaim, commissioned back in 1948 and, by the 1970s, limited to operations at depths of just 90 metres.

The name was not chosen at random. In December 1872 a wooden corvette called HMS Challenger sailed from Portsmouth with most of her guns taken out and laboratories built in their place, under Captain George Nares, with Professor Wyville Thomson in charge of the scientists aboard. She came home three and a half years later having covered 68,890 nautical miles, stopped at 362 stations to take soundings, temperatures, water samples and dredge hauls, and identified 4,717 species that nobody had known existed. Before her, the prevailing scientific opinion was that nothing could live in the deep ocean at all.

That voyage is generally taken as the moment oceanography became a science rather than a hobby, and it produced fifty volumes of report that took twenty years to publish. It also produced a sounding in the Mariana Trench of 4,475 fathoms, which is why the deepest known point on the surface of the Earth is called the Challenger Deep. Handing that name to a ship built in 1981 to work on the seabed at 300 metres was a considerable compliment and, given how her career actually went, a slightly cruel one.

Reclaim had earned her keep in her day: within three months of her own commissioning, Petty Officer Wilfred Bollard broke the Royal Navy's diving depth record aboard her, in June 1951 she located the wreck of the submarine HMS Affray, lost with all 75 hands and, to date, the last Royal Navy submarine ever lost at sea, and in 1956 Senior Commissioned Boatswain George Wookey pushed a standard flexible diving suit to 600 feet, a record that still stands.

Reclaim's own story, including the Affray search and the record dive, is set out in more detail in the article on HMS Brereton, who worked with her in a Norwegian fjord in 1974 to lift a ditched helicopter off the bottom.

Naval Staff Requirements approved in 1976 called for a far more capable vessel able to operate on the seabed to depths of 300 metres, fitted with a saturation diving system that could accommodate twelve divers in a chamber amidships, an ambitious specification for the era.

Reclaim paid off in 1979, five years before Challenger was ready for sea, leaving a gap that the Navy plugged by chartering the offshore support vessel MV Seaforth Clansman to keep Naval Party 1007, the Fleet's saturation and deep-diving team, operational in the meantime.

A Ship With Secret Cold War Purposes

Beyond her publicly stated research role, HMS Challenger was designed around nine classified functions connected to Britain's Cold War defence posture, including securing the strategic nuclear deterrent, recovering lost nuclear weapons, and supporting seabed surveillance devices monitoring Soviet submarine movements, a properly significant and highly sensitive set of intended missions for what outwardly appeared to be a fairly ordinary support ship.

Recovering lost nuclear weapons was not a hypothetical entry on that list. On 17 January 1966 an American B-52 collided with its tanker at thirty-one thousand feet over Spain and dropped four hydrogen bombs on the village of Palomares. Three were found on land inside a fortnight. The fourth went into the Mediterranean, and it took eighty days, a fleet of ships and eventually the research submersible Alvin to find it, lying at two and a half thousand feet with its own parachute draped over it. Getting it up was worse: the recovery vehicle sent down to hook it managed the job largely by getting tangled in the parachute lines.

Two years later a B-52 came down on the ice off Thule in Greenland with much the same cargo, and the search there ran for months. Those two accidents concentrated minds everywhere. If you keep nuclear weapons and you fly them, or float them, over water, then sooner or later you will need to find one on the bottom, and you will need to do it faster than anybody else can get there. That is the sentence behind the staff requirement, and it is why a country with a submarine-based deterrent decided in 1976 that it wanted its own deep recovery ship rather than a telephone number for somebody else's.

That kind of shopping list was very much of its moment: the Cold War's least-publicised front line ran along the seabed itself, where both sides laid, tapped and occasionally sabotaged undersea sensor arrays and cables, and a ship able to work unnoticed at real depth was a genuinely valuable asset to have on the books, whatever it cost to keep her there.

It is worth being specific about what that seabed war looked like, because the best-documented example of it reads like fiction. From 1971 the Americans ran an operation called Ivy Bells against a Soviet military cable laid under the Sea of Okhotsk, between Kamchatka and the mainland. Divers found the cable at about four hundred feet and fitted a pod some twenty feet long around it, which read the signals passing through by induction without cutting or piercing anything, and recorded weeks of traffic at a time onto tape.

It ran for the best part of a decade and it was lost to a man in debt. In January 1980 an NSA employee named Ronald Pelton walked into the Soviet embassy in Washington and, over the following five years, sold what he knew for around thirty-five thousand dollars and expenses. In 1981 American satellites picked up a Soviet flotilla, salvage vessel included, sitting precisely over the tap. The pod was gone. It is now on display in the Central Museum of the Armed Forces in Moscow, which is a fair summary of how that particular round finished.

That is the world Challenger's nine classified functions were written for: a war fought at four hundred feet by divers, cables and recording pods, in which the side that could work quietly and deep had an advantage nobody could see. It is also why a ship that never made her design work still cost the Ministry of Defence a hundred and fifty-four million pounds before anybody admitted it.

An Ambitious, and Notoriously Troublesome, Design

Her main tool was a Towed Unmanned Submersible, a heavy remotely operated "garage" towed up to two kilometres behind the ship on its own umbilical and rated to work at depths of 5,000 metres, technology so far ahead of its time that it reportedly never worked properly throughout her whole career. A central moon pool amidships lowered an unusually large diving bell for saturation divers working down to 300 metres, a system so thirsty for helium that simply running it was ruinously expensive. She was also designated to carry the Royal Navy's LR5 submarine rescue submersible, though at a top speed of around 15 knots, Challenger would have made a rather leisurely response to a submarine crew genuinely trapped on the seabed.

A Troubled Construction and an Unfulfilled Mission

HMS Challenger's construction was beset by faulty equipment, manufacturing challenges, fires and other damage that pushed her well beyond her initial £80 million budget, the final bill running to around £154 million, roughly half a billion pounds in today's money, and repeatedly delayed her from achieving full operational status. Years later, a fire during a refit at Immingham on the Humber destroyed much of her diving system's wiring, handing the Ministry of Defence the excuse it needed to finally pay off a ship whose running costs it had long since tired of covering.

Despite continued trials through the late 1980s, she never managed to deliver on the demanding technical requirements she had been designed around, though she did rack up some genuine achievements, several of them still only partly declassified. Her divers carried out the first ever transfer of personnel between two pressurised submersibles at depth, and in one memorably tidy piece of salvage work she recovered a Sea Harrier that had come down in the sea off Portland from the carrier HMS Ark Royal. Her most useful hour arguably came in March 1989, when the container ship MV Perintis sank in a Channel storm roughly 35 miles north of Guernsey carrying tonnes of the pesticide lindane along with drums of permethrin and cypermethrin; Challenger and her divers were sent to recover the toxic cargo, helping head off what could have been a serious pollution incident, even if one heavy lindane container was ultimately lost for good on the seabed near the Hurd Deep.

Paid Off as the Cold War Ended

HMS Challenger was decommissioned in 1990, effectively written off as a troubled experiment just as the collapsing Warsaw Pact and shrinking Cold War defence budgets made continued investment in her difficult to justify, laid up and offered for sale, a disappointing end for a ship that had once been intended to safeguard Britain's most sensitive undersea secrets.

Her withdrawal effectively ended the Royal Navy's brief flirtation with an in-house deep-diving mothership: by the early 1990s the whole capability had been abandoned for cost reasons, with submarine rescue and deep salvage work handed to chartered civilian specialists ever since, much as it had been in the gap before Challenger herself first arrived.

The rescue submersible she was meant to carry outlived her by twenty years, and its story is the ending Challenger never got. In August 2000 the LR5 was flown to Norway for the Kursk, and never dived: the Russian government took too long to accept foreign help, and all one hundred and eighteen men aboard died.

Five years later it went differently. On 5 August 2005 the Russian rescue submersible AS-28 fouled the anchor cable of a hydrophone array in Berezovaya Bay off Kamchatka and was pinned to the bottom at about a hundred and ninety metres with seven men inside. Moscow asked for help within hours this time. Twenty-nine Britons flew out from Scotland with a Scorpio 45 remotely operated vehicle in the back of an aeroplane, cut the cables away on the 7th, and all seven Russians surfaced alive.

So the capability the Royal Navy decided it could not afford to keep in a ship of its own did eventually do exactly what it had been imagined for, out of a cargo hold, at a few hours' notice, for somebody else's submarine. Challenger, by then, was working off the Namibian coast under another name, dragging a crawler across the seabed and pulling up diamonds.

An Unexpected Second Career Mining Diamonds

HMS Challenger's post-Navy life took a genuinely remarkable turn. Purchased by Subsea Offshore in 1993 for hazardous waste decontamination work in the Baltic and North Atlantic, a project that never really got going, she instead sat laid up on the River Tyne for years before the Namibian Minerals Corporation bought her and had her converted at the Nauta Shipyard in Gdynia, Poland, at a cost of around 200 million South African rand. Renamed MV Ya Toivo in August 2000, after Andimba Toivo ya Toivo, the Namibian independence leader who had spent sixteen years imprisoned on Robben Island and was released in 1984, the very year Challenger herself was commissioned into the Royal Navy, the former Cold War recovery ship made her first diamond recoveries off the Namibian coast that December.

NAMCO's own diamond dream proved almost as troubled as Challenger's naval one: a damaged seabed crawler tipped several of its subsidiaries into provisional liquidation in early 2001, a rescue refinancing partly backed by the Israeli diamond dealer Lev Leviev bought only a temporary reprieve, and the company folded into liquidation again in February 2003.

Two months later, the former Royal Navy vessel, once designed to recover lost nuclear weapons in the depths of the Cold War, was purchased by the mining giant De Beers for twenty million US dollars, a striking final chapter for a ship whose original mission had never quite come to fruition, but whose deep-sea capabilities found an entirely unforeseen and notably lucrative second purpose. Still working today as Ya Toivo for De Beers Marine Namibia, she is 149 metres long, carries a crew of around 90, and can stay at sea for months at a stretch while a giant tracked crawler mines diamond-bearing gravel from the seabed, a rather less dramatic mission than hunting Soviet submarines, but one she has now been doing for considerably longer than she ever served the Royal Navy.